Apparatus for the control of the rolling speed of articles

ABSTRACT

Apparatus for controlling the rolling speed, for example, of cylindrical articles down a slope comprises a flexible tube laid down the slope. Liquid is contained in the tube, the arrangement being such that rolling of an article down the tube causes a pressure rise in liquid in the tube forward of the article. Liquid leakage occurs under the article from the part of the tube forward of the article to the part of the tube behind the article, thereby controlling the rolling speed of the article to a constant velocity. A constant leak area is defined in the tube under the article, for example, by placing a longitudinal spacer strip in the tube.

United States Patent APPARATUS FOR THE CONTROL OF THE ROLLING SPEED OF ARTICLES 10 Claims, 14 Drawing Figs.

US. Cl 193/32,

193/7 Int. Cl 865g 11/20 Field of Search [56] References Cited UNITED STATES PATENTS 3,347,587 IO/I967 Frost 294/87 FOREIGN PATENTS 1,052,898 9/1960 Germany 193/32 1,066,492 10/1959 Germany 193/32 Primary Examiner-Harvey C. Hornsby Assistant Examiner-Merle Maffei Almrney- Larson, Taylor and Hinds ABSTRACT: Apparatus for controlling the rolling speed, for example, of cylindrical articles down a slope comprises a flexible tube laid down the slope. Liquid is contained in the tube, the arrangement being such that rolling of an article down the tube causes a pressure rise in liquid in the tube forward of the article. Liquid leakage occurs under the article from the part of the tube forward of the article to the part of the tube behind the article, thereby controlling the rolling speed of the article to a constant velocity. A constant leak area is defined in the tube under the article, for example, by placing a longitudinal spacer strip in the tube.

PATENTED M1631 Ian sum 1 OF 5 PATENTED M1831 um 502,349

sum 5 [IF 5 APPARATUS FOR THE CONTROL OF THE ROLLING SPEED OF ARTICLES BACKGROUND OF THE INVENTION This invention relates to apparatus for controlling the speed of rolling of articles down a slope. I

In a manufacturing line employing a number of adjacent series flow process machines there is a requirement for transfer of articles between machines in the line. The probability of asynchronous operation of related machines and the need for temporary shut down of some of the machines for adjustment and minor maintenance necessitates interprocess article storage facilities. In the case of a manufacturing line dealing with the manufacture of articles which can roll, transfer of articles between adjacent machines can be effected by rolling of the articles down a slope from one machine to another and the articles can be brought to rest in a store at the bottom of the slope.

Such a transfer system is simple and utilizes a minimum of moving mechanical parts. Further advantages inherent in the system are that it has a variable storage capacity and can handle articles of different dimensions. Also all the articles in the store are advanced towards the bottom of the slope on removal of the leading article from the slope.

For the handling of articles which are liable to be damaged by impact one with another such a transfer system should include means for limiting article transfer velocity down the slope to a relatively low stable value. Also articles should be deposited in the store at the bottom of the slope ina' cushioned manner, for exampleby the provision of article braking means having rapid deceleration characteristics.

SUMMARY OF THE INVENTION 7 According to the present invention equipment for controlling the speed of rolling of an article down a slope comprises a flexible walled container extending down the slope and containing a fluid, means being provided defining a limit to the degree of constriction of the cross section of the container under the weight of a rolling article. I

The means for defining a limit to the degree of constriction of the cross section of the container under the weight of a rolling article may be formed so that the degree of constriction of the cross section of the container varies as the article rolls down the slope so as to provide a programmed variation in th rolling speed of the article.

In a particular arrangement the means for defining a limit to the degree of constriction of the cross section of the container under the weight of a rolling article may comprise spacer means extending longitudinally inside the container. Altematively spacer means may be provided extending longitudinally alongside the container. In the case of an arrangement having spacer means inside the container these may comprise a spacer strip of rectangular cross section and the width or thickness of the spacer strip may vary along its length so as to provide a variation in the degree of constriction of the cross section of the container under the weight of a rolling article thus obtaining a programmed variation in the rolling speed of the article. In the case of spacer means running alongside the article the height of the spacer means may vary along its length so as to obtain a programmed variation in the rolling speed of the article.

DESCRIPTION OF THE DRAWING Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

FIG. 1 is a side elevation of apparatus in accordance with the invention, v

FIG. 2 is an end elevation of the apparatus shownin FIG. 1,

FIGS. 3 and 4 are sectional details ofthe apparatus shown in FIGS. 1 and 2, the sections being respectively along the lines IIIIII and IVIV in FIG. 1,

FIGS. 5, 6 and 7 are graphs illustrating the operational characteristics of apparatus as shown in FIGS. I and 2,

FIG. 8 is a side elevation of a modified form of apparatus in accordance with the invention,

FIG. 9 is a side elevation of a further form of apparatus in accordance with the invention,

' FIG. '10 is a cross section along the line XX in FIG. 9,

FIG. 11 is a side elevation of a modified form of the apparatus shown in FIG. 9,

FIGS. 12 and 13 are cross sections along the lines XII-XII and XIII-XIII in FIG. 10,

FIG. is an isometric detail of a form of apparatus suitable for rolling of articles down long slopes.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The arrangement shown in FIGS. 1 and 2 comprises a sloping ramp '1. Two 1 inch layflat" polyethylene tubes 2 (i.e. of one inch width when laying flat) and of 0.005 inch wall thickness are laid down the ramp 1 parallel to each other. The tubes 2 are sealed at their lower ends 3 and maintained liquid filled by a header tank 4. As shown in FIG. 3 a full length spacer strip 5 of polyethylene is placed in each tube 2.

In operation a cylindrical article 6 on rolling-down the sloping tubes 2 causes a pressure rise in the liquid contained in the lower sealed ends of the tubes 2. As shown in FIG. 4 at any position of the article 6 on the tubes 2 each tube 2 is depressed onto the spacer strip 5 by the article 6 sothat the cross section of the tube 2 is constricted and a small leak area 7 is defined in the tube 2 on either side of the spacer strip 5 immediately below the article 6. As the article6 rolls down the tubes 2 liquid leaks through the leak areas 7 from the lower ends of the tubes 2 forward of the article 6 to the upper ends of the tubes 2 behind the article 6. The resulting effect is that a retarding force is applied on the article 6 controlling the rolling speed of the article at a constant value. For example an increase in rolling speed of the article 6 necessitates an increased flow rate of liquid through the leak areas 7 and thus an increase of pressure of liquid'in the tubes 2 forward of the article 6. Thus under these conditions the retarding force acting on the article is increased and the article is decelerated.

Conversely a decrease in rolling speed of the article occasions a reduced flow rate of liquid through the leak areas 7 and a reduction of pressure of liquid in the tubes 2 forward of the article 6. In this case therefore the retarding force of the article is reduced resulting inacceleration of the article until steady state conditions are once more achieved.

The parameters influencing the operational characteristics of the arrangement are tube material, diameter and thickness, fluid viscosity, density and static head, the size of the leak areas 7, the slope of the ramp 1 and the diameter and weight of the article 6.

FIG. 5 is a graph showing the terminal speed characteristics of an article plotted against the sine of the slope (Angle B FIG. I) of the ramp 1 under the following operational parameters:

1. Tubes 2, 1 inch layflat polyethylene and of 0.005 inch thickness.

2. Tubes 4. water filled (viscosity =30 Redwood sees.) at a minumum static head of 3 inches.

3. Article diameter of0.63 inches.

4. Article weight 3.5 lbs.

The four curves numbered l to IV in FIG. 5 relate respectively to arrangements having leak areas 7 of 0.016, 0.011, 0.007 and zero square inches respectively, the size of the leak areas 7 being determined by the width and thickness of the spacer strips 5.

FIGS. 6 and 7 are similar graphs relating respectively to arrangements in which the tubes 2 are filled with an oil of viscosity 85 Redwood seconds (FIG. 6) and an oil of viscosity 300 Redwood seconds (FIG. 7).

Over the speed range as indicated by the chain dotted rectangles in FIGS. 5, 6 and 7, it is apparent that constant speeds are produced, the terminal speed being approximately proportional to the slope of the ramp 1 and the leak area 7, but decreasing with increasing liquid viscosity.

As the slope of the ramp 1 is increased the component of force exerted by the article 6 normal to the ramp 1 decreases whilst the component of force acting parallel to the ramp 1 increases, thus generating an increased hydraulic pressure in the tubes 2 forward of the article 6 until lift off of the article 6 occurs. In this phenomenon the article 6 lifts on the tubes 2 so that the article no longer constricts the tubes 2 sufficiently to make a face to face seal with the spacer strips 5. Thus lift off of the article 6 results in an increase of the effective leak area 7. However the occurrence of lift off at higher ramp slopes is not a drawback as constant speed characteristics continue to exist. The onset of lift off is indicated in each of FIGS. 5, 6 and 7. As lift off if not synonymous with acceleration, articles can be fed onto the ramp 1 at a high velocity and will be rapidly decelerated to the constant velocity characteristic of the particular arrangement.

The hydraulic pressure of the liquid in the tubes 2 which provides for retardation of the rolling speed of the article 6 to a constant velocity is proportional to the slope of the ramp 1. At a critical limiting slope break away of the of the article 6 will occur, in that the article 6 is then subjected to a net accelerating force. The onset of such break away is also shown in FIGS. 5, 6 and 7. However break away occurs only at slopes of the ramp 1 considerably steeper that those required for efficient article transfer (e.g. 19 compared with Reduction of the diameter of tubes'employed (e.g. to five eights inches layflat size) results in the occurrence of a higher terminal velocity at any particular slope of the ramp 1, although lift off and break away occur later on the speed slope characteristics, i.e. at high slope angles.

Retardation of the rolling speed of an article is maintained satisfactorily when more than one article is rolling down the ramp I at the same time, whether the articles are adjacent or separated by a length of the ramp 1.

By local variation in the leak area 7, for example by variation of the thickness and/or the width of the spacer strips 5 along their length, speed programming can be achieved so that adjacent rolling articles can be dispersed or collected, or articles can be slowed locally if required, for example when passing a counting device or approaching a process station.

It is also practical to employ gases instead of liquids in the arrangements described above. For example compressed air may be fed through a pressure reducing valve to the lower end of each of the tubes 2 in the arrangement of FIGS. 1 and 2. With one inch layflat polyethylene tubes 2 of 0.005 inch wall thickness and a leak area 7 of 0007 square inches, using an air feed pressure of inches water gauge, cylinder rods of 0.63 inches diameter and 3.5 lb. weight were found to roll down a 5 slope at a velocity of about 2 inches per second.

FIG. 8 of the drawing shows a modification of the invention applicable as a brake in a storage area for articles at the bottom of a transfer ramp. The modification comprises a length of polyethylene tube 8 partially filled with liquid 9 and containing a spacer strip 10. Air is excluded from the tube 8 which is closed at both ends.

In a particular arrangement employing two 1 inch layflat" polythene tubes 8, laid parallel to each other down a sloping ramp II, a tube length of 2 feet was suitable for storage of 0.63 inch diameter cylindrical rods. A stop member 14 is provided at the bottom end ofthe ramp 1]. As can be seen in FIG. 8 with a number of rods 12 stored on the tubes 8 a reservoir volume 13 of liquid exists at the bottom end of each tube 8, a quantity of liquid is trapped between each of the rods 12 and liquid 9 in the tubes 8 above the rods 12 provides for the braking of further rods rolling down the ramp 11 into the rod store. Braking of the rods can be achieved in a relatively short distance -e.g. in 2 inches from a velocity of 2 feet per second to a velocity of 2 inches per second.

FIGS. 9 and 10 of the drawings show an alternative arrangement more suitable for the handling of heavy articles. In this arrangement a liquid filled polyethylene tube 2 is laid along a channel comprising a sloping base plate 15 and side flanges 16. The height of the flanges 16 determines the amount of constriction of the tube 2 by a rolling article 6 and thus defines thesize of the leak area 7 immediately below the'article 6. In the arrangement of FIG. 9 the side flanges 16 are of constant height so that the article 6 is constrained to roll down the slope at constant speed.

FIGS. 11, 12 ad 13 show a similar arrangement to that of FIG. 9 but having side flanges 16 which decrease in height above the base plate 15 in passing down the slope. As in FIG. 9 the channel may be formed with the base plate 15 and the side flanges 16 integral with each other in which case the side flanges 16 are tapered by machining. Alternatively the arrangement may be made adjustable to accommodate articles of various weights and sizes. As shown in FIG. 11 variation of the effective taper of the side flanges 16 may be achieved by having the base plate 15 fixed and by pivoting each of the side flanges 16 on the base plate 15 by a pivot pin 17. The side flanges 16 are swiveled relative to the base plate 15 in order to alter the effective taper of the side flanges 16 relative to the base plate 15. In an alternative arrangement the side flanges 16 are fixed and the base plate is pivoted at its upper end from the side flanges 16. In the arrangement of FIG. 11 when an article 6 is at the top of the slope the leak area 7 defined below the article is large (See FIG. 13) so that deceleration of the article is low and hence the rolling speed of the article is correspondingly high. As the article 6 rolls down the slope the constriction of the tube 2 by the article 6 increases and thus the leak area 7 defined below the article gradually decreases because of the decreasing height of the side flanges 16 above the base plate 15. As shown in FIG. 12 at the bottom of the slope the leak area 7 defined below the article is small. Therefore in the arrangement of FIG. I] the article 6 has a high rolling speed at the top of the slope but is gradually decele'rated in speed as it passes down the slope and is finally brought to a low terminal velocity at the bottom of the slope.

In all arrangements the length of the tubes 2 is limited to about 20 feet for a 5 slope. However as shown in FIG. 14, for longer slopes a series of tubes 2 may be provided sequentially down the slope with the adjacent ends of the tubes 2 overlapping.

We claim:

1. Equipment including a means for controlling the speed of rolling an article down a slope comprising a flexible walled container extending down the slope and containing a fluid, said container being arranged on the slope such that the article lies on the container and hence exerts a gravity force thereon tending to constrict the cross section of the container, means being provided for defining a limit to the degree of constriction of the cross section of the container, under the weight of a rolling article, the maximum constriction occurring at any instant, under the center of the article taken in a direction substantially perpendicular to the surface of the slope, and a smaller constriction occurring immediately in front of and behind the center of the article, wherein at its maximum the constriction leaves remaining at least a small leak area for the flow of fluid by the article as the article rolls down the slope.

2. Equipment for controlling the speed of rolling of an article down a slope as claimed in claim I wherein the means for defining a limit to the degree of constriction of the cross section of the container under the weight of a rolling article are of a form such that the degree of constriction of the cross section of the container under the weight of a rolling article varies as the article rolls down the slope so as to provide a programmed variation in the rolling speed of the article.

3. Equipment including a means for controlling the speed of rolling of an article down a slope comprising a flexible walled container extending down the slope and containing a fluid, said container being arranged on the slope such that the weight of the article rests on the container and henceexerts a force tending to constrict the cross section of the container spacer means being provided for extending longitudinally inside the container so as to define a limit to the degree of constriction of the cross section of the container under the weight of a rolling article.

4. Equipment for controlling the speed of rolling of an article down a slope as claimed in claim 3 wherein the spacer means comprises a spacer strip of rectangular cross section extending longitudinally inside the container, the width and the thickness of the spacer strip governing the degree of constriction of the cross section of the container under the weight of a rolling article. 7

5. Equipment for controlling the speed of rolling of an arti-' cle down a slope as claimed in claim 4 wherein the width of the spacer strip varies along its length so as to provide a variation in the degree of constriction of the cross section of the container under the weight of a rolling article thus obtaining a programmed variation in the rolling speed of the article.

6. Equipment for controlling the speed of rolling of an article down a slope as claimed. in claim 4 wherein the thickness of the spacer strip varies along its length so as to provide a variation in the degree of constriction of the cross section of the container under the weight of a rolling article, thus obtaining a programmed variation in the rolling speed of the article.

7. Equipment including a means for controlling the speed of rolling an article down a slope comprising a flexible walled container extending down the slope and containing a fluid,

said container being arranged on the slope such that the weight of the article rests on the container and hence exerts a force tending to constrict thecross section of the container, spacer means for defining a limit to the degree of constriction of the cross section of the container under the weight of a rolling article, said spacer means comprising a set of flanges extending down the slope along each side of the container wherein the article, rolling down the slope lies on the flanges as it contacts the container, the height of the flanges at any point determining the degree of constriction of the container at that point along the slope.

8. Equipment for controlling the speed of rolling of an article down a slope as claimed in claim 7 wherein the height of the spacer means varies along its length so as to provide a variation in the degree of constriction of the cross section of the container, thus obtaining a programmed variation in the rolling speed of the article.

9. Equipment for controlling the speed of rolling of an article down a slope as claimed in claim 8 wherein the height of the spacer means decreases progressively in passing from the top to the bottom of the slope, so as to provide a progressive increase in the degree of constriction of the cross section of the container under the weight of a rolling article as the article rolls down the slope, thereby subjecting the article to a progressive deceleration as it rolls down the slope.

10. Equipment for controlling the speed of rolling of an arti cle down a slope as claimed in claim 1 wherein a number of flexible walled containers are placed sequentially down the slope with the ends of adjacent containers overlapping. 

1. Equipment including a means for controlling the speed of rolling an article down a slope comprising a flexible walled container extending down the slope and containing a fluid, said container being arranged on the slope such that the article lies on the container and hence exerts a gravity force thereon tending to constrict the cross section of the container, means being provided for defining a limit to the degree of constriction of the cross section of the container, under the weight of a rolling article, the maximum constriction occurring at any instant, under the center of the article taken in a direction substantially perpendicular to the surface of the slope, and a smaller constriction occurring immediately in front of and behind the center of the article, wherein at its maximum the constriction leaves remaining at least a small leak area for the flow of fluid by the article as the article rolls down the slope.
 2. Equipment for controlling the speed of rolling of an article down a slope as claimed in claim 1 wherein the means for defining a limit to the degree of constriction of the cross section of the container under the weight of a rolling article are of a form such that the degree of constriction of the cross section of the container under the weight of a rolling article varies as the article rolls down the slope so as to provide a programmed variation in the rolling speed of the article.
 3. Equipment including a means for controlling the speed of rolling of an article down a slope comprising a flexible walled container extending down the slope and containing a fluid, said container being arranged on the slope such that the weight of the article rests on the container and hence exerts a force tending to constrict the cross section of the container spacer means being provided for extending longitudinally inside the container so as to define a limit to the degree of constriction of the cross section of the container under the weight of a rolling article.
 4. Equipment for controlling the speed of rolling of an article down a slope as claimed in claim 3 wherein the spacer means comprises a spacer strip of rectangular cross section extending longitudinally inside the container, the width and the thickness of the spacer strip governing the degree of constriction of the cross section of the container under the weight of a rolling article.
 5. Equipment for controlling the speed of rolling of an article down a slope as claimed in claim 4 wherein the width of the spacer strip varies along its length so as to provide a variation in the degree of constriction of the cross section of the container under the weight of a rolling article thus obtaining a programmed variation in the rolling speed of the article.
 6. Equipment for controlling the speed of rolling of an article down a slope as claimed in claim 4 wherein the thickness of the spacer strip varies along its length so as to provide a variation in the degree of constriction of the cross section of the container under the weight of a rolling article, thus obtaining a programmed variation in the rolling speed of the article.
 7. Equipment including a means for controlling the speed of rolling an article down a slope comprising a flexible walled container extending down the slope and containing a fluid, said container being arranged on the slope such that the weight of the article rests on the container and hence exerts a force tending to constrict the cross section of the container, spacer means for defining a limit to the degree of constriction of the cross section of the container under the weight of a rolling article, said spacer means comprising a set of flanges extending down the slope along each side of the container wherein the article, rolling down the slope lies on the flanges as it contacts the container, the height of the flanges at any point determining the degree of constriction of the container at that point along the slope.
 8. Equipment for controlling the speed of rolling of an article down a slope as claimed in claim 7 wherein the height of the spacer means varies along its length so as to provide a variation in the degree of constriction of the cross section of the container, thus obtaining a programmed variation in the rolling speed of the article.
 9. Equipment for controlling the speed of rolling of an article down a slope as claimed in claim 8 wherein the height of the spacer means decreases progressively in passing from the top to the bottom of the slope, so as to provide a progressive increase in the degree of constriction of the cross section of the container under the weight of a rolling article as the article rolls down the slope, thereby subjecting the article to a progressive deceleration as it rolls down the slope.
 10. Equipment for controlling the speed of rolling of an article down a slope as claimed in claim 1 wherein a number of flexible walled containers are placed sequentially down the slope with the ends of adjacent containers overlapping. 